<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>after</title>
<style type="text/css">
div {
	width: 300px;
	height: 100px;
	border: 1px solid #000;
}
div::after {
	content: "我在内容的后面";
}
</style>
</head>
<body>
<div>伪元素</div>
</body>
</html>